Experimental data for the rate of CO₂ release from seawater under vacuum at 30 °C and ambient pressure at 100 °C

The research hypothesis underlying this dataset is that the rate of CO₂ release from seawater under boiling conditions depends on water residence time and pressure, and that these dynamics differ significantly between vacuum and ambient pressure. To test this, we experimentally quantified CO₂ release under two representative conditions: vacuum boiling at 30 °C (20 mbar) and atmospheric boiling at 100 °C. The dataset shows time-resolved measurements of pH and total inorganic carbon (TIC), corrected for evaporative volume loss to capture the actual CO₂ release over time. The results demonstrate an initial rapid outgassing of dissolved molecular CO₂, followed by a slower release as bicarbonate is converted into CO₂. Notably, the release kinetics differ between vacuum and atmospheric boiling, highlighting the role of pressure and temperature in controlling the equilibrium and conversion reactions. Data were gathered using seawater samples from the North Sea (The Hague, October 2024), analyzed at the Geoscience Laboratory of Utrecht University. These measurements can be interpreted as empirical validation of CO₂ release dynamics during seawater evaporation and depressurization, which are essential for marine Carbon Dioxide Removal (mCDR) research and the design of processes such as Ocean Thermal Energy Conversion (OTEC), multi-effect distillation (MED), and mechanical vapor recompression desalination (MVR). The dataset can be directly reused to validate theoretical models, assess release kinetics, and optimize process equipment for carbon removal applications.